井口房和通风机房附近20米内,不得有烟火或用火炉取暖。
参考答案:对
I showed an old friend of mine around the city, surprise, the changes had been so great.
A.whose
B.which
C.to whose
D.to which
下列不属于转子式流量计的是()。
A.腰轮式
B.卵轮式
C.靶式
D.螺杆式